Autoconfiguration IPv6 nodes

[Aseem]

Hi,

In autoconfiguration process the book says (pg746) that "An RA message also happens to be a multicast packet that's sent to each node's multicast address...". My ques. is:

1) As the Interface Id is prefixed with FE80 making the address look like this - FE80::0260:d6FF:FE73:1987 and the RA packet is being sent as multicast then how is the node able to receive it as multicast addresses start with FF only.

2) And is the Global Prefix not required to make an IP truly globally unique then what is the exact purpose of the "u" bit. Can there not be such a case where 2 LAN cards on different networks have same MAC address and if both have the u bit turned on then their global uniqueness can only be figured out from the Global prefix or am i at mistake somewhere in understanding the finer nuances of IPv6.